Question

An imide is a functional group similar to an acid anhydride. Instead of an oxygen between two carbonyls, an imide has a nitrogen between two carbonyls. Suggest a method for making the imide shown below starting with pentanedioic acid and benzyl amine. O=C1CCCC(=O)N1Cc1ccccc1

Short answer

React pentanedioic acid with benzyl amine to form an amide, followed by cyclization to form the imide.

Step-by-step solution

- Understand the Structure of the Imide

The goal is to form an imide, which has a nitrogen atom between two carbonyl groups. For the imide shown in the exercise, the nitrogen atom is bonded to a cyclic structure, specifically a six-membered ring with a nitrogen and two carbonyl groups.

- Identify the Reactants

The reactants are pentanedioic acid (a dicarboxylic acid) and benzyl amine (an amine with a benzyl group). The pentanedioic acid has two carboxylic acid groups (-COOH), and the benzyl amine has an amine group (-NH2) attached to a benzyl group (a phenyl group attached to a -CH2-).

- Create a Cyclic Structure

To form a six-membered ring imide, the pentanedioic acid must react with the benzyl amine such that the amine group attacks one of the carboxylic acids, resulting in the formation of an amide. Concurrently, the second carboxylic acid group can undergo intramolecular cyclization, leading to cyclization and loss of water molecules.

- Formation of an Amide

The benzyl amine reacts with one of the carboxylic acid groups of pentanedioic acid. This forms an amide and releases a molecule of water (condensation reaction).

- Intramolecular Cyclization

The remaining carboxylic acid group undergoes dehydration to form an imide. The internal nucleophilic attack by the amide nitrogen onto the second carbonyl group closes the ring and another water molecule is removed.

- Verify Structural Formula

Confirm the resultant chemical structure to ensure it matches the given imide. You should now have a six-membered ring structure with a nitrogen atom between two carbonyl groups, attached to a benzyl group.

Key concepts

organic chemistry

Organic chemistry focuses on compounds containing carbon atoms. It delves into the structure, properties, and reactions of organic molecules. In our exercise, we're working with pentanedioic acid, a dicarboxylic acid, and benzyl amine, an amine.

The foundation of organic chemistry involves understanding how different functional groups interact to form new compounds. Here, we combine an amine with a dicarboxylic acid to form an imide, a functional group characterized by a nitrogen atom bonded between two carbonyl groups. By understanding the basic principles of organic chemistry, you can easily grasp how provided reactants interact to form more complex structures.

cyclization reactions

Cyclization reactions involve the formation of a ring structure within a molecule. In our context, pentanedioic acid reacts with benzyl amine forming a six-membered ring imide.

This process begins by reacting benzyl amine with one carboxylic group of pentanedioic acid to form an amide, releasing a water molecule (a typical condensation reaction). Next, the second carboxylic acid group reacts intramolecularly with the amide's nitrogen, leading to the formation of a cyclic imide. Here, another water molecule is released. Thus, cyclization involves both the formation of a new ring structure and the elimination of smaller molecules.

functional groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In this exercise, we deal with various functional groups - carboxylic acids (-COOH), amine (-NH2), and carbonyl groups (C=O) - and transition to an imide group.

The transformation involves multiple steps where the functional groups interact:

• The carboxylic acid group reacts with the amine to form an amide.
• An intramolecular reaction between the amide and the remaining carboxylic acid group forms the imide.

Understanding these functional groups' properties and reactivity helps predict and design the synthesis of complex molecules in organic chemistry.

amide formation

Amide formation is a crucial reaction in organic chemistry, often involved in forming more complex compounds like imides. It's typically a reaction between an amine and a carboxylic acid.

In our exercise, benzyl amine reacts with pentanedioic acid:

• The amine group (-NH2) of benzyl amine attacks the carbonyl carbon of one carboxylic acid group, forming an amide bond and releasing water, in a condensation reaction.
• This newly formed amide can further react in subsequent cyclization to form the target imide structure.

Amide formation is characterized by a nucleophilic substitution reaction where water is typically a by-product, reflecting in the elimination steps of cyclization in imide synthesis.